Stress echocardiography based RV-pulmonary coupling predicts rehospitalization and mortality in HFpEF

BACKGROUND: Right ventricular-pulmonary artery (RV-PA) coupling is a key prognostic marker in heart failure with preserved ejection fraction (HFpEF), but the role of stress echocardiography (SE) remains unclear. We aimed to assess its prognostic value and develop a predictive model for HFpEF-related rehospitalization and cardiovascular mortality. METHODS: In this prospective cohort study, 81 patients with HFpEF underwent comprehensive transthoracic echocardiography at rest and during peak exercise. Assessments included right heart function, pulmonary artery pressure, and RV-PA coupling parameters, with correlation analyses performed accordingly. Clinical outcomes of interest were HF-related rehospitalization and cardiovascular mortality. Predictive modeling was conducted using least absolute shrinkage and selection operator (LASSO) regression, and clinical impact curves (CIC) were generated. Event-free survival was estimated and compared between groups using Kaplan-Meier analysis. RESULTS: At baseline, 54.3 % of patients with HFpEF exhibited elevated mean pulmonary arterial pressure (mPAP). In terms of RV performance, the event group showed significantly lower RVFAC and FWLS at rest, while RVESAi remained consistently higher at both rest and peak exercise (P < 0.05). LASSO regression identified age, E/e'-peak, and FWLS/SPAP-peak as independent predictors of adverse events. These variables were incorporated into a nomogram model, which demonstrated robust discriminative ability (C-index = 0.879; AUC = 0.90; sensitivity = 0.950; specificity = 0.804). Decision curve analysis and clinical impact curves further confirmed its clinical utility. Kaplan-Meier analyses revealed significantly different event-free survival probabilities between high and low groups stratified by FWLS/SPAP-peak, TAPSE/SPAP-peak, and FORCE-peak. CONCLUSION: The nomogram integrating age, E/e'-peak, and FWLS/SPAP-peak provides a non-invasive, stress-based tool for early risk stratification in HFpEF. The findings highlight impaired RV-PA coupling under exercise stress as a key pathophysiological substrate contributing to adverse outcomes.